Electric lamp for miners&#39; use.



No. 656,977. Patented Aug. 28, I900.

' L. HORWITZ.

ELECTRIC LAMP FOR MINERS USE.

(Application filed Feb. 21, 1899.)

3 Sheets-Sheet l.

(No Model.)

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THE Mumps wzrzns cu. mom-uma. WASH N No. 656,977. Patented Aug. 28 1900.L. HORWITZ.

ELECTRIC LAMP FOR MINERS USE.

(Application filed Feb. 21, 1899.)

3 Sheets-Sheet 2.

(No Model.)

Fly 5.

HHHHHU HHHHHH HHHHHH IHHHHH (No Model.

Patented Aug. 28, I900.

L. HURWITZ.

ELECTRIC LAMP FOR MINERS USE.

(Application filed Feb. 21, 1899.)

3 Sheets-Sheet 3.

UNITED STATES PATENT Orrica.

LEO IIORWITZ, or BERLIN, GERMANY.

ELECTRIC LAMP FOR MINERS USE.

SPECIFICATION forming part of Letters Patent No. 656,977, dated August28, 1900.

Application filed February 21, 1899. Serial No. 706 ,898. (N0 model.)

T0 cvZZ whom it may concern:

Be it known that I, LEO I-Ionwrrz, a subject of the King of Prussia,German Emperor, residing at Berlin, in the Kingdom of Prussia, Germany,have invented certain new and useful Improvements in or Relating toElectric Lamps for Miners Use, (for which I have applied for a patent inGermany, filed July 22, 1898; in France, filed July 28, 1898, No.280,069; in England, filed August 22, 1898, No. 18,057, and in Belgium,filed August 23, 1898, No. 137,545,) of which the following is aspecification.

This invention relates to an electric switching device for twolamp-circuits, one of which is automatically switched in if the other isburned out or gets damaged throughany cause or other, and vice versa.

This switching device is in particular suitable for electric lamps forminers use, and in the accompanying drawings it is applied to such alamp.

The switching device consists, essentially, of an electromagnet thearmature of which actuates two contacts. The electromagnet attracts itsarmature when one lamp is burning; but it ceases to do so when the lampis burned out, so that the two contacts are closed and the circuitpasses through the other lamp. A handswitch is'also provided for thepurpose of switching in one lamp or neither of the two lamps. Thehand-switch has, moreover, for its purpose to press, prior to theswitching in of one lamp, the armature against the cores of the magnet,and owing to its construction it prevents the armature when it isswitched in from leaving the magnetic-attraction field and effects inconsequence in switching in the attraction of the armature. In anothermodified construction the switching is arranged in such a manner thatwhen one lamp is burned out the other lamp begins to glow; but thecircuit of the latter is continually opened and closed, so that by theflickering of the light it is indicated that one lamp is burned out andthe other is switched in. In the third modified construction theswitching is so simplified that only when one lamp is burned out theother lamp is put in circuit, while the inverse does not take place inthis construction.

The electric switching device is shown in the accompanying drawings.

Figure 1 represents a diagram'of the circuits of the first form'of theminers lamp. Fig. 2 is a section through the contact-pieces of thehand-switch fitted to the miners lamp for switching the lamp in and out.Fig. 3 shows a diagram of the electrical connections of the second formof the invention. Fig. at shows the miners lamp in elevation, the frontcover being removed to show the inner arrangement of the parts. The modeof connection corresponds to the simplest of the three forms of theinvention. Fig. 5 is a longitudinal section through the lamps, showingthe arrangement of the ball-joint for the reflector and that of theaccumulator; and Fig. 6 is a section through the lamp, showing theconnection of the accumulator with the same.

In the position shown in Fig. 1 of the handswitch t the latter pressesagainst the armature n of the electromagnet on, so that the contact isopened at p q. At'the same time the insulated screw g,provided on thearmature w, presses against the platespring b, so that simultaneouslythe contact is also opened at c. For rendering the lamp h glowing thehandswitch 15 is placed on thecontact-piece 2. The armature at under theaction of the platespring T will be retracted a little from the magnetm; but the dimensions are so that the switch twill come in contact withthe piece 2 before the contacts 13, q, and c are closed. By theconnection of t and 2 the electromagnet m is energized and attracts atonce its armature n, holding it fast as long as the lamp switched in isburning. The current flows then from the positive terminal& of thesource of the current through the switch-lever t, the contact-piece 2,to the wire-circuit 1, into the lamp h, and thence it returns throughthe circuit 1 and the electromagnetm to the negative terminal 7. It thelamp becomes now burned out, owing to the destruction of the bulb or ofthe filament, the electromagnet ceases to attract its armature, and thecontacts p, q, and c are closed by the action of the spring 1. Thecurrent flows now from a through if 2 2 0 b c 2 to the lamp h and thencethrough r p q back to the negative terminal '7. The lamp h is thereforenow burning in place of lamp h, but the magnet-coil is not switched inand the armature attracted, as the coil is in shunt to the circuit, andthe coil offers to the current a greater resistance than the circuit. Ifit is desired from the first to use only the second lamp so that thelamp 7b serves as a reserve lamp, when the first is burned out thehand-lever 6 is brought from the position shown in Fig. 1 over thecontact 2 on the contact -3,the current then flowing from 4 through i,3, conducting-wire 2, lamp 71., circuit 1", electromagnet m, and thenceback to the negative terminal 7. If this lamp h is burned out, theelectromagnet ceases to attract its armature, the contacts p, q, and care then closed, and the current runs from 4 through Z 3 circuit 2 0 0 21 to the lamp h and thence through 1-1) back to the terminal 7. Theelectromagnet is also in this case not energized, because it is in shuntto this circuit and offers to the current a greater resistance than thecircuit. The contactpieces 1 2 3 of the hand-switch If are cut in orcurled in such a manner, Fig. 2, that they offer to the movement acertain resistance, but do not hinder the lever from moving from onecontact-piece to the other, so that the spring 1 can rapidly pull theswitch-lever from one contact-piece to the other.

In the simpler modified construction illustrated in Fig. 3 the armature71 is provided only with a contact 2) 1. If the switch-lever f isbrought from the position shown in Fig. 3 from the contact-piece 1 tothe contactpiece 2, the current runs from at through 2, 2, circuit 1,lamp 71', and thence back through the circuit l and the electromagnet mto the terminal 7. If thelamp 7t is burned out, the magnet ceases toattract its armature, and the current runs from t If through 2, qp, n,3, lamp 7t, and 1 through the electromagnet wt to the terminal 7. Thearmature is therefore attracted again and the play is repeated anew, sothat a to-and-fro motion is im parted to the armaturen and the contactq, and in consequence also the circuit passing through the lamp h iscontinually closed and broken, so asto cause the light to flicker,indicating thus that the lamp h is burned out. In the same manner thelamp h may be switched in in placing the switch-lever on contact-pieceThe circuit is then as follows: at, 2., 3, circuit 2, lamp 71., circuit1 electromagnet in, and terminal 7. Here also the armature 71 iscontinually attracted and set free, and the flickering of the lamp 7Lindicates that the lamp h is destroyed.

The third modification of the switch is shown in Fig. 1- as applied toan electric miners lamp. The other two modifications may, however, alsobe used in such lamps. The current flows here from the terminal 4.throught f, contact-piece 2, electromagnet in, wire 1 and lamp h andthence back to terminal 7. The magnet attracts its armature, thusopening the contact 1) q. If the lamp is switched 7L becomes burned out,the lamp 72/ in through the contact 1) q in the same mannor as describedin the other modifications. If it is desired to use the lamp 7t, theswitching-lever t is placed on contact 3. Also in this arrangementit mayparticularly be pointed out, as in the other two modifications, that thesure switching in is effected by the fact that prior to and during theswitching in of the lamp 72, the switching lever it strikes against thearmature '11. and holds it within the magnetic field so long as itreceives electromagnetism.

As it is very important for the electric switching device abovedescribed to keep the iron parts free from any residual magnetism, thereis provided a particular arrangement of a storage battery for the minerslamp. The accumulator u is fitted on each side with two lead-strips t wo '20, each pair of which 1; o and w w is connected with theaccumulator. If the accumulator is so put in the apparatus that thelead-strips o and to come in cont-act with plate-springs 4E and 7, thecurrent runs in a given direction-for instance, from the positive pole oof the accumulatorover plate-spring 4, through the whole apparatus, andthrough the plate-spring 7 back to the negative pole w of theaccumulator. If now after the accumulator has been charged afresh it isput back in the apparatus in such a manner that strip 10 comes incontact with spring 4 and lead-strip o with spring 7, the current runsin a direction that is the reverse of that in which it ran before-thatis to say, from positive terminal o over 7, through the apparatus, andback over 4 to the negative terminal to. Any traces of magnetism (theresidual magnetism) that might remain in the iron parts of theelectromagnets are thus neutralized, so that an adherence of thearmatures to the magnets is prevented.

It may still be mentioned that in these miners lamps one lamp h isconnected, by means of a balljoint, to the handle, which serves forcarrying or hanging the lam p,while the second lamp h is fitted to thefront of the box or casing. According as the workman will use one lampor the other he switches it in by means of the hand-switch. If the lampbecomes burned out, he is not in the dark, as at once the second lamp isautomatically switched in.

It is evident that the switching device may be used also for many otherpurposes where an instantaneous substitution of one lamp by another isrequired.

I claim- 1. In a portable electric lamp, the combination with aswitch-lever in the main circuit of an automatic switching device,comprising an electromagnet energized by the main current controlled bysaid switch-lever and including a glow-lamp, of a spring-actuatedarmature automatically opening and closing a shunt-circuit and providedwith an extension to be engaged by said switch-lever, a second glow-lampin the shunt-circuit and connected with another shunt-circuit controlledby the said switch-lever and allowing either lamp to be thrown intocircuit by the operator, and a battery for supplying the main circuit,substantially as described.

2. A miners lamp, comprising two glowlamps, a hand-switch, a battery, acasing therefor, contacting strips for the battery and casing, and anautomatic switching device comprising an electromagnet the armature ofwhich actuates a contacting device switching in or out either lamp, thecontacting strips of the battery and casing being arranged in such amanner that after each fresh charge of the battery the latter may beplaced in the apparatus so that one pair of strips on the battery comesin contact with a different pair of strips on the casing whereby thedirection of the current is reversed and any residual magnetism in theapparatus is neutralized, substantially as described.

3. In a miners lamp, the combination with two glow-lamps, of ahand-switch, a battery, circuits and connections substantially asdescribed, and an automatic switching device comprising an electromagnetthe armature of which actuates the contacts controlling the circuits insuch a manner that when one lamp goes out the other one is successivelyand alternately switched in and out of the circuit so as to cause thislamp to flicker, substantially as described.

In witness whereof I have hereunto signed my name in the presence of twosubscribing witnesses.

LEO HORWITZ.

Witnesses:

GUSTAV GOHOUL, GUSTAV HiILsMANN,

